Added GTK-Doc related autotools options
Removed swe-glib-date-time.[ch] files

They were a wrong way to start at all
Removed gettext.h from the sources. GLib's i18n functions are used instead
Added some documentation to test GTK-Doc
Added GSWEMoment to the build objects
Added a GNOME specific autogen.sh

It is from the nautilus project, and does the same thing as the old
one, but in a more sane way.